In recent years, due to the human diet containing high-calorie, high-fat, and high-glycemic index food as well as insufficient exercise, more and more people are getting gastrointestinal diseases and cardiovascular diseases, and the age of getting such diseases is getting younger. In tennis of the expenditure in medical care, the gastrointestinal diseases (including colorectal cancer and rectal cancer), the cardiovascular diseases (including heart attacks, stroke, and hypertension) and the related expenses have caused too much pressure on people's health and medical resources. In order to prevent from gastrointestinal diseases and cardiovascular diseases, many nutritionists have been promoting the importance of healthy diet and indicating that impropriate diet is a main reason of getting each of the adult chronic diseases and accelerating aging.
According to the World Health Organization (WHO), 75% of the modern people are under the sub-healthy state, 25% of the people are having diseases, and only 5% of the people are truly healthy. Among the three factors (genetics, living environment, and diet nutrition) that affect the health, only the diet nutrition may be personally controlled. A conventional diet management method provides information for disease or nutrition analysis by filling up personal data sheets. However, since the record-filling steps are too tedious so that a user's willingness to use is inevitably reduced.
Hence, assisting the user to manage diet intakes and diet habits by using information technology is one of the ultimate goals in medical and information fields. Additionally, assisting the user to collect personal diet activity as well as analyzing the characteristics of the provided diet information by using information technology is one of the recent research topics.